1. Field of the Invention
The invention relates generally to miniature non-semiconductor electrical and electronic elements used in printed circuit board applications and particularly to an improved microelectronic component carrier package and method of manufacturing the same.
2. Description of Related Technology
Dual in-line chip carrier packages (DIPs) are well known in the field of electronics. A common example of a DIP is an integrated circuit, which is typically bonded to a ceramic carrier and electrically connected to a lead frame providing opposed rows of parallel electrical leads. An example of an electronic circuit configured in a DIP is a toroid. A toroid is a doughnut shaped piece of magnetic material, together with one or more coils of current carrying wire, typically between AWG 24 to AWG 50, which are wrapped about the doughnut so that the magnetic flux is almost completely confined within it.
The DIPs are traditionally grouped together on a printed circuit board. The DIPs may be integrated with the printed circuit board by inserting the leads of the DIP into holes on the printed circuit board. Alternatively, the DIPs may be surface mounted, having their leads attached to the surface of the printed circuit board with solder. The integrated circuit and ceramic carrier are normally encased in a rectangular plastic or ceramic housing from which the leads extend. Plastic chip carriers are more widely used in commercial and industrial applications where the environment is less sever and where cost is a factor.
The continuing miniaturization of electrical and electronic elements and high density mounting thereof have created increasing challenges relating to fabrication and reliability. Accordingly, there is a need to be able to fabricate increasingly small and reliable microelectronic packages which contain the miniaturized electrical and electronic elements, and to do so at a minimum cost.
Due largely to their design and construction, prior art methods of manufacturing microelectronic component packages require a lengthy series of process steps including drawing and aligning the fine leads associated with the components into proper position, cutting them to the desired length, placing the lead ends in contact with the leadframe, heat stripping and terminating the leads within the package to form a permanent junction, and encapsulating the leads and carrier. This series of steps necessarily requires substantial hand-labor and processing time, thereby adding significantly to the cost of producing each device.
FIG. 1 shows a typical prior art component package formed by the aforementioned process. The disadvantages of the component package shown in FIG. 1 is that it occupies an appreciable volume within the package, thereby necessitating a larger overall package. Additionally, the lack of electrical separation between individual leads in this system may increase the probability of electrical faults between leads as well. Since the individual leads are hand-cut and hand-positioned prior to mating the subassembly to the leadframe, sometimes the leads are mis-cut or mis-positioned allowing the leads to touch each other, causing a short circuit or not touch the leadframe causing an open circuit. Manufacturers are in need of an assembly system and a method to insure that the leads are cut to a consistent length and that the leads remain electrically isolated after they are connected to a leadframe.
Currently, there are few tools available to assist the manufacturer in cutting the leads frames to a consistent length. Manufacturers need a tool specifically designed for this purpose. In addition, it would be preferable if the tool could facilitate the joining of the leads to the leadframe as part of the cutting process. The tool should also be able to handle the mass production of component carriers so that the leads of more than one component carrier can be cut at a time.
Accordingly, it would be most desirable to reduce the number of processing steps necessary to manufacture a microelectronic component package, while at the same time allowing for the overall size of the package to be reduced, and its reliability increased.